In many situations, it is desirable to manage networking equipment, servers, and computers distributed across a network. Early keyboard, video and mouse (“KVM”) switches enabled access to remote devices from distances of up to fifteen hundred (1,500) feet over dedicated Category 5 (“CAT5”) cables. Newer systems utilize existing networks such as local area networks (“LANs”) or wide area networks (“WANs”) to enable a user workstation to access the keyboard port, video port, and cursor control device port of a remote device. If the distance between the user workstation and the remote device is great enough, the Internet is commonly utilized to enable remote control of computers from a user workstation.
Early solutions for enabling control of remote computers via a network or the Internet were implemented using software. For example, the software program pcAnywhere allows remote access to a computer through the Internet or a LAN. Remote computer access programs, such as pcAnywhere, typically require installation of software on each remote computer. To access a remote computer, a user of the user workstation selects the desired remote computer from a list and (optionally) enters an appropriate username and password. Once access has been granted to the remote computer, the user utilizes the keyboard, video monitor, and cursor control device attached to the local user workstation to operate and control the remote computer.
To obviate the need to install a software program on each remote computer, solutions have been proposed whereby a remote access device is coupled to each remote computer to communicate with the user workstation. In these solutions the intermediate remote access device receives video from a remote computer, and using a software program (e.g., pcAnywhere) transmits the video to a user workstation. The software program is also used to receive keyboard and cursor control device signals from the user workstation. The remote access device then supplies these signals to the keyboard port and cursor control device port of the remote computer. Using an intermediate remote access device eliminates the need for software to be installed on each remote computer, but still relies on proprietary software, such as pcAnywhere.
Solutions have been proposed that fully eliminate the use of software programs such as pcAnywhere. These hardware solutions typically use a KVM switch which is accessible over the Internet or LAN via a common protocol, such as TCP/IP. Such hardware solutions may also utilize a modem to connect to the Internet. Generally, a user or system administrator accesses the remote computers attached to the KVM switch utilizing an Internet web-browser or client software associated with the KVM switch. Once the remote computer has been selected, video signals from the remote computer are routed to the user workstation's video monitor. Simultaneously, a user can control the remote computer using a local keyboard and/or cursor control device. The KVM switch may additionally include a connection to the power source of the remote computer for a hard reboot in case of system failure. These solutions are generally limited to KVM and/or power control via a hard-wired connection. These solutions are also limited because they do not offer wireless access, serial control, scalable solutions, etc. In short, these solutions generally only provide one function for a user workstation; KVM access to a single remote device.
Recently there has been a proliferation of wireless technologies to enable computers to communicate and share resources. For example, the Bluetooth and Institute of Electrical and Electronics Engineers (“IEEE”) 802.11 standards are two rapidly developing technologies that allow computers to wirelessly communicate with one another. Devices are commercially available that comply with the 802.11 standard and enable wireless TCP/IP communications over distances of up to three hundred (300) feet or more. For example, PCMCIA wireless cards enable laptops to communicate utilizing the TCP/IP protocol. Many 802.11 compatible wireless local area networks (“WLANs”) are now utilized in lieu of, or in conjunction with, local area networks. In contrast, Bluetooth devices are generally utilized for shorter range communication, utilizing lower transmission rates than 802.11 compliant devices.
The 802.11 standard, ratified by the IEEE in 1997, is a wireless communications standard generally utilized for networking, file sharing and Internet connection sharing. In 1999, two extensions to the 802.11 standard were added, 802.11a and 802.11b. The 802.11a standard operates in a frequency range of 5 Gigahertz (“GHz”) at speeds of up to 54 Megabits per second (“Mbps”). The 802.11b standard (also known as WiFi), was designed to be more affordable, and operates in the 2.64 GHz range at speeds of up to 11 Mbps. With the proliferation of 802.11b devices, the 802.11g standard was recently ratified which allows for 802.11a speeds in 802.11b compatible frequencies.
All 802.11 standards allow computers to communicate wirelessly, eliminating the need for hubs, routers, switches, etc. The 802.11 standard allows for the creation of WLANs, which use the same TCP/IP communication protocols as traditional wired LANs. With commercially available wireless communication devices, two computers can communicate from up to three hundred (300) feet away. However, with repeaters, stronger antennae, signal boosters, etc., can increase this range. Today, wireless networks are available in airports, coffee shops, college campuses, etc.
Importantly, the 802.11 standard allows for at least two different network configurations: (1) an infrastructure mode in which all traffic passes through a wireless “access point”; and (2) an “ad-hoc” mode (or “peer-to-peer” mode) in which devices communicate without an access point. Independent of the mode, the 802.11 standard supports wireless networks that offer the same communications (e.g., TCP/IP, file sharing, Internet sharing, etc.) as a wired connection.
In the infrastructure mode, devices communicate through a wireless access point. An access point is similar to a hub, or router (but without wires), in that it receives and transmits all data between wireless devices. Advantages of the infrastructure mode include increased scalability, increased range of communication, and access to a wired network. By adding additional access points, the network can grow without undue burden on any one device. An access point can also be utilized to increase the range of communications. Cascading access points and signal boosters can overcome the three hundred (300) foot communication limit of most 802.11 devices. Finally, traditional access points also offer access to a wired network. Therefore, an infrastructure network easily adapts to communicate with an Ethernet LAN or an Internet connection.
An ad-hoc network is more dynamic—it can be created and torn-down easily without additional hardware. Computers can enter and leave the network so long as the computer is configured to access a wireless network with the same service set identifier (“SSID”) as other computers in the network. Generally, an SSID is a sequence of alphanumeric characters that identifies the ad-hoc network. The ad-hoc network also advantageously requires no external hardware. An ad-hoc network can be created with multiple computers alone, so long as each computer has a WiFi compatible communications device.
An important feature of the 802.11 standard is the availability of multiple channels of communications, utilizing Direct Sequence Spread Spectrum (“DSSS”) technology, to allow for this feature. DSSS is a technology that allows for the transmission of data over a range of frequencies, which decreases the power utilized at any one frequency. Therefore, DSSS allows for fast communications with little interference. Thus, DSSS permits an 802.11 network to include multiple communications channels. Further, the wireless network can co-exist with other wireless devices that operate in similar frequency ranges.
Generally, in an ad-hoc network, one of the available channels (the FCC currently allows for eleven (11) total channels) is utilized as a “broadcast” channel. The broadcast channel allows devices to “discover” other devices in range of communication and to transmit messages that are received by all devices. Thus, the broadcast channel is a critical feature of the 802.11 standard that allows for the creation of ad-hoc networks in which devices can automatically join and leave the network. The network then utilizes one of a variety of algorithms such as a spokesman election algorithm (“SEA”) or a broadcast/flooding algorithm for all other communications. In SEA, one computer is “elected” to head the network and tracks the addition of other computers to and from the network. In a broadcast/flooding algorithm, generally all messages are sent to all computers. If an access point is utilized, then no such algorithms are necessary. Instead, the access point can be utilized to ensure that all messages reach the correct destination.
Systems that enable wireless access of a remote device are currently known in the art of computer management. For example, one such system comprises a single receiver and a single transmitter that together allow a user to access a remote computer using a keyboard, video monitor, and cursor control device. In this system, both the receiver and the transmitter are enabled for wireless communication. The receiver, coupled to the keyboard and mouse, receives keyboard and mouse data and wirelessly transmits this data to the transmitter. The transmitter is coupled to a remote computer and supplies the data to the keyboard and mouse ports of this remote computer. Simultaneously, the transmitter receives video data from the remote computer and transmits this data wirelessly to the receiver where it is displayed on the video monitor coupled to the receiver. Thus, this system enables extended length access of a single remote computer through a wireless connection.
Another known system consists of a switching device for controlling multiple remote computers where the switching device comprises a wireless transmitter and a wireless receiver. The switching device is configured to enable a user to select from among multiple computing devices and wirelessly link a peripheral device with a selected computing device for user interaction. In this system, the switching device initially develops a list of available computing devices. A user chooses from this list and the switching device establishes a wireless link with the corresponding computing device. Thus, this wireless switch only enables one connection between a user and a remote computer at any instance. Further, each of the computing devices must also have wireless communication capabilities to enable wireless communication with the switch.
A method for switching the utilization of a shared set of wireless I/O devices between multiple computers is also known in the art. This method includes the utilization of a software based switching mechanism where wireless protocols enable the sharing of wireless peripheral devices between multiple computers. A wireless data packet (a “token”) is utilized to transfer control of the I/O devices utilizing a “master-slave” relationship for the transfer of control. The token is the form of computer-to-computer wireless command utilized to transfer control of a wireless peripheral device from one device to another. Thus, in this known system, server-to-server communications are necessary for transferring the control of a wireless peripheral. Further, in this system only one computer can control a set of wireless peripherals at a time.
In another known system for accessing computer systems in a computer network, each computer system provides and receives operator interface data signals containing user output and input information. Central to this system is a wireless administrator device that allows a system operator to remotely control a plurality of computer systems interconnected through a communications network. The wireless administrator device includes a wireless communications module that operates in “transmit” and “receive” modes to communicate with the wireless communication modules coupled to the computer systems. The wireless administrator device includes an operator interface with a video display, mouse and keyboard to enable user interaction in a selection mode or a control mode. The interface includes a manual connect button that allows the administrator to display on the video a list of available computer systems that may be accessed. Upon selection of a computer, the administrator remotely controls the computer through the operator interface.
Finally, systems are also known that provide a wireless interface between a remote host computer and a personal digital assistant (“PDA”). In one such system, the PDA presents the user with a graphical user interface (“GUI”) allowing for input by way of a passive stylus, which can be used in a pen mode or a mouse mode. The PDA also includes a transceiver that communicates wirelessly with the transceiver of a remote computer. The transceiver allows the wireless device to access the remote host computer over a wireless LAN or through a peer-to-peer network. The system also allows a user to view available remote host computers through the GUI of the wireless device and to access the programs and files of the remote computer. The remote computer in turn, transmits display commands to the wireless device. A similar system utilizes Bluetooth communications to enable a PDA to recognize and identify all compliant remote devices by transmitting a broadcast message that is received by compliant remote devices. In this system, the PDA includes a GUI to display a rendering of a mechanism that can be utilized to control a remote device. For example, the rendering might be of an on/off switch. The PDA receives input from a stylus, and translates this input into a command for the remote device.
In view of the foregoing, a need clearly exists for a comprehensive multifunction remote device management system capable of wirelessly operating and controlling a number of remote servers, file/print servers, headless servers, network appliances, serial IT equipment, switches, routers, firewalls, security interfaces, application servers, load balancers, and environmental controls as their associated power supplies are connected to a remote control device. Such a system should offer a variety of functions to a user including controlling devices via KVM access, controlling devices via serial port access, and controlling the power supply of devices. The system should also be accessible via a wireless and/or hard wired connection. Furthermore such a system should easily scale to allow for the access and control of many remote devices simultaneously by many different user workstations. Finally, such a system should enable both serial and KVM access to such remote devices.